fly_speed = argument0;
top_bound = argument1;
bottom_bound = argument2;

robber_y = random_range(top_bound,bottom_bound);
if(round(random(1)==0)){
    robber = instance_create(20,robber_y,obj_robber_left);
    robber.hspeed = fly_speed;
    
}else{
    robber = instance_create(940,robber_y,obj_robber_right);
    robber.hpeed = -fly_speed;
}
